Telephone apparatus



9 I c. N. REIFSTECK ET AL 2 I TELEPHONE APPARATUS Filed Dec. 1, 1953 ATTORNEY Carl MBEQfJEcIU,

Patented Nov. 9, 1937 UNITED STATES PATENT oer-ice TELEPHONE APPARATUS corporation of Delaware Application December 1, 1933, Serial No.

2 Claims. (l. 179-103) Our invention relates to telephone apparatus and particularly to telephone hand-sets.

At the present time there is a tendency to employ batteryless operated telephone systems for many applications. These systems generally include two electro-mechanical units (such as electro-magnetic units) at each station, one unit being utilized as a transmitter and the other unit being utilized as a receiver. Some systems have employed a single electro-magnetic unit at each station, the unit being used both as transmitter and receiver, but in such systems it has been necessary to hold tfie unit first at the mouth and then at the ear during a conversation.

is It will be apparent that, while the abovementioned single unit construction is the cheaper of the two designs, ithas serious disadvantages.

Perhaps the most important of these is that it is inconvenient to use. Another disadvantage is that one person cannot interrupt or "out in on another person's conversation.

An object ,of our invention is to" provide telephone apparatus utilizing a single electro-mechanieal unit for both transmitting and receiving which does not have the above mentioned disadvantages.

A further object of our invention is to provide a combined transmitter and receiver unit having a single electro-mechanical unit therein which may be used simultaneously as'a transmitter and as a receiver.

In a preferred embodiment of our invention, we utilize a hollow tube in the shape of a French hand-set. An electro-magnetic unit is so posi- 35 tioned in the tube that it may be operated as a transmitter by speaking into one end of the tube. It also iunctions as a receiver for producing sound waves appearing at the other .end of the tube.

40 Other objects, features, and advantages of our invention will appear from the following description taken in connection with the accompanying drawing in which,

Fig. 1 is a view taken in cross-section of one 45 embodiment of our invention, and

Figs. 2 and 3 are schematic diagrams of other embodiments of our invention.

Referring to Fig. l, we provide a combined transmitter and receiver in the form of a French 50 hand-set. The combined unit comprises a hollow tube I open at both ends and shaped in the form of the usual French hand-set, whereby one end of the tube may be utilized as the transmitting end and the other end of the tube utilized 55 as the receiving end.

In the jembodiment illustrated, the tube I is made of soft rubber,\but it will be understood that any suitable material suchas hard rubber or metal may be employed.-

A bead 3 is 'provided'at' .thetransmitter end 5 of the tube and provided with a circular groove 5 in which an electro-mechanical innit"? is mounted. This unit comprises jai can'or face plate 9 having openings I I in the center. thereof and a back plate l3 which isfastened to the face plate 9 10 at its periphery. in anysuitable manner. A. dia' .phragm I5 vis clamped at its-periphery between the face plate 9 'and the backvlpl'ate I3.

- Thediaphragm I5 is connected to the upper end of an. armature I'l by 'means of a pin i9.

The armature I'I is preferably of the cantilever type, rigidly supported-attire bottom end by means of structure not shown in the drawing. Armature I l is positioned between pole pieces 2i and 23 of a magnet structure which includes two permanent magnets 25 and 2'! positioned on opposite sides of the pole pieces 2i and 23. The magnetic structure'is supported from the back plate I3 by means of a bracket member 29.

A magnet coil 3| surrounds the armature I1 25 so that any'movement of the armature causes a variation in the flux threading the magnet coil whereby voltages are induced therein in ac- .cordance' with the armature movement. Also, this action is reversible since any variation in current supplied to the magnet coil 3I causes a corresponding movement of the armature IT and of the diaphragm I5 to which it is connected.

The receiver end of the tube I also is provided with a head 33 which has a circular groove 35 35 therein. A cap 31 which is provided with openings 39 in the center thereof is mounted in the circular groove 35. Both the cap 31 and the electro-mechanical unit I are assembled in the rubber tube I by deforming or stretching the rub- 40 ber beads 33 and 3, respectively, to permit the insertion of these devices in the grooves.

The back plate I3 of the electro-mechanical unit 1 has openings 4| therein so that sound waves set up by the back side of the diaphragm I5 can travel through the tube I to the receiver end.

Thus it will be seen that by talking into the transmitter end of the tube, the electro-mechanical unit I is caused to produce electrical energy in accordance with the sound waves, which energy may be transmitted over a telephone line to the electro-mechanical unit of a similar telephone hand-set. When voice signals are impressed upon the electro-magnetic coil 3| from a telephone line, the diaphragm i5 is caused to vibratein accordance therewith and sound waves are transmitted from the back side of the diaphragm through the tube I to the receiving end.

Since a person using the hand-set has the receiver end of the tube at his ear while talking, he may be interrupted by the person at the other end of the line at any time as in the case of a conventional telephone system.

Although the electro-mechanical unit I has been described somewhat in detail, it should be understood that any electro-mechanical unit which will function both as a transmitter unit and as a receiver unit may be employed in practicing our invention.

It is not necessary that the electro-mechanical unit be located at the transmitter end of the tube, and in some cases it may be preferable to locate it elsewhere. For example, it may be located at the middle of the tube as illustrated in Fig. 2, or at the receiver end of the tube, as illustrated in Fig. 3.

Referring to Fig. '2, the hand-set comprises a hollow tube 43 open at both ends, the transmitter end being provided with a cap 45 having openings 44 in the center, while the receiver end is provided with a cap 46 ha'ving openings 41 in the center. A diaphragm I8 is positioned transversely of the tube 41 and connected to the armature 49 of an electro-mechanical unit SI of any suitable construction. It will be noted that in this construction the sound waves, which operate the unit 5| as a transmitter, travel from the transmitter end of the tube to the right-hand side of the diaphragm 48. The sound waves produced by incoming speech signals travel from the left-hand side of the diaphragm 48 to the receiver end of the tube.

Referring to Fig. 3, the hand-set comprises a hollow tube ii'open at both ends and having an electro-mechanical unit positioned at the receiver end. The transmitter end is provided with a cap 51 having openings 59 in the center.

it"he unit 55 may be of any suitable construction, the same as the unit illustrated in Fig. 1,

' the appended claims.

for ei'rample, and may be mounted in the same manner as that unit. It includes a diaphragm 6| which is connected to the armature ll of the unit. A cap having openings 81 in the center is preferably provided for protecting and supporting the diaphragm.

In any of the above described embodiments of our invention it may be desirable to provide the hollow tube with openings or restrictions to give the tube the proper acoustic qualities. In the- We claim as our invention:

1. A telephone unit comprising a hollow tube of resilient material andshaped to have a mouthpiece at one end and an earpiece at the other end, a diaphragm located in saidtube and positioned transversely thereof, and a single reversible electro-mechanical unit having an armature connected to said diaphragm, said unit also being located inside said tube and being resiliently supported thereby.

2. A telephone unit comprising a hollow tube of resilient material open at both endsand so shaped that one end may be held near a person's mouth while the other end is held near his car, an electro-mechanical unit having a diaphragm.

said unit being located inside said tube with its diaphragm positioned transversely thereof and being resiliently supported thereby, and means for causing said unit to produce electrical energy in response to sound waves striking one end and to produce sound waves which appear at said other end in response to electrical energy supplied to said unit.

- v CARL N. REH'BTEOK. GLENN L. DIMMICK. 

